RESUMO
The importance of food contaminants in the link between diet and cancer has been widely demonstrated. Therefore, different physical and chemical strategies for the control of human exposure to such dietary carcinogens has been explored; however, most of these strategies are complex, costly, and have low efficiency which limited their applications. Hence, microbiological methods have been receiving more attention. Recent in vitro and in vivo studies have indicated that lactic acid bacteria (LAB) and yeast may act as dietary carcinogen-binding agents. This review describes the promising protective role of strains belonging mainly to the Lactobacillus, Bifidobacterium and Saccharomyces genera by acting as dietary carcinogen-binding agents. This property suggests that these microorganisms may have a protective role by reducing the bioaccessibility of dietary carcinogens, thereby decreasing their toxic effects. The mechanisms by which the binding process takes place have not been completely elucidated; thus, the possible underlying mechanisms and factors influencing carcinogens-binding will be addressed.
Assuntos
Lactobacillales , Neoplasias , Carcinógenos/toxicidade , Fermentação , Humanos , Lactobacillus , Saccharomyces cerevisiae , LevedurasRESUMO
In Mexico, close to 200 fermented products have been described, of which, approximately 20 are beverages. They were obtained through rustic and ancestral fermentation methods by different indigenous Mexican communities; most of them were used in ceremonies, agricultural work, and other occasions. For their elaboration, different substrates obtained from plants are used, where uncontrolled and low-scale spontaneous anaerobic fermentation occurs. In Mexico, some of these products are considered as nutritional sources and functional beverages; the study of those products has revealed the presence of multiple compounds of biological importance. Additionally, elder generations attribute healing properties against diverse illnesses to these beverages. The aim of this review is to highlight the available information on twelve traditional Mexican fermented beverages, their traditional uses, and their fermentation processes along with toxicological, chemical, nutritional, and functional studies as seen from different areas of investigation. In the literature, pulque, cocoa, and pozol were the beverages with the greatest amount of described health properties; sendechó and guarapo were less characterized. Polyphenols, gallic and ferulic acid, anthocyanins and saponins were the most abundant molecules in all beverages. Finally, it is important to continue this research in order to determine the microorganisms that are involved in the fermentation process, as well as the organoleptic and beneficial properties they lend to the traditional Mexican fermented beverages.
Assuntos
Antocianinas , Alimentos Fermentados , Bebidas , Fermentação , MéxicoRESUMO
The aim of this study was to assess the protective effect of the intracellular content obtained from potential probiotic bacteria against acrylamide-induced oxidative damage in human erythrocytes. First, the antioxidant properties of 12 potential probiotic strains was evaluated. Two commercial probiotic bacteria were included as reference strains, namely, Lactobacillus casei Shirota and Lactobacillus paracasei 431. Data showed that the intracellular content from four strains, i.e., Lactobacillus fermentum J10, Lactobacillus pentosus J24 and J26, and Lactobacillus pentosus J27, showed higher (P < 0.05) antioxidant capacity in most methods used. Thereafter, the intracellular content of such pre-selected strains was able to prevent the disturbance of the antioxidant system of human erythrocytes exposed to acrylamide, thereby reducing cell disruption and eryptosis development (P < 0.05). Additionally, the degree of oxidative stress in erythrocytes exposed to acrylamide was significantly (P < 0.05) reduced to levels similar to the basal conditions when the intracellular content of Lact. fermentum J10, Lact. pentosus J27, and Lact. paracasei 431 were employed. Hence, our findings suggest that the intracellular contents of specific Lactobacillus strains represent a potential source of metabolites with antioxidant properties that may help reduce the oxidative stress induced by acrylamide in human erythrocytes.
Assuntos
Acrilamida/farmacologia , Antioxidantes/farmacologia , Misturas Complexas/farmacologia , Lacticaseibacillus casei/química , Lacticaseibacillus paracasei/química , Lactobacillus pentosus/química , Limosilactobacillus fermentum/química , Acrilamida/antagonistas & inibidores , Antioxidantes/química , Catalase/metabolismo , Células Cultivadas , Cromanos/farmacologia , Misturas Complexas/química , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Lacticaseibacillus casei/metabolismo , Limosilactobacillus fermentum/metabolismo , Lacticaseibacillus paracasei/metabolismo , Lactobacillus pentosus/metabolismo , Malondialdeído/antagonistas & inibidores , Malondialdeído/metabolismo , Oxirredução , Estresse Oxidativo , Probióticos/química , Superóxido Dismutase/metabolismoRESUMO
In this study, a global metabolite profile using Raman spectroscopy analysis was obtained in order to predict, by an in silico prediction of activity spectra for substance approach, the bioactivities of the intracellular content (IC) and cell wall (CW) fractions obtained from Lactobacillus casei CRL 431 and Bacillus coagulans GBI-30 strains. Additionally, multifunctional in vitro bioactivity of IC and CW fractions was also assessed. The metabolite profile revealed a variety of compounds (fatty acids, amino acids, coenzyme, protein, amino sugars), with significant probable activities (Pa > 0.7) as immune-stimulant, anti-inflammatory, neuroprotective, antiproliferative, immunomodulator, and antineoplastic, among others. Moreover, in vitro assays exhibited that both IC and CW fractions presented angiotensin-converting enzyme-inhibitory (> 90%), chelating (> 79%), and antioxidant (ca. 22-57 cellular antioxidant activity units) activities. Our findings based on in silico and in vitro analyses suggest that L. casei CRL 431 and B. coagulans GBI-30 strains appear to be promising sources of postbiotics and may impart health benefits by their multifunctional properties.
Assuntos
Bacillus coagulans/metabolismo , Lacticaseibacillus casei/metabolismo , Metaboloma , Probióticos/química , Biologia ComputacionalRESUMO
Hibiscus sabdariffa and Camellia sinensis are traditionally consumed as beverages and are good sources of health-promoting phenolic compounds. The objective of this work was to use response surface methodology to develop an optimized functional beverage with high total phenolic content, antioxidant capacity, and acceptable for potential consumers. Optimum infusion conditions were 4.9 g of hibiscus calyces or C. sinensis leaves/100 ml of water at 26 â for 291 min. These conditions yielded a total phenolic content of 14.80 ± 1.4 and 33.02 ± 0.34 mg gallic acid equivalents/100 ml for hibiscus and green tea, respectively. The optimized beverages were combined in a 7:3 (hibiscus:green tea, v/v) ratio; a consumer preference test showed that this combination had an acceptable taste according to untrained panelists. A chromatographic analysis showed that this formulation contained flavonoids, phenolic acids, and anthocyanins as its main components. Our data suggested that hibiscus and green tea phenolic compounds were efficiently extracted using near-ambient temperature water for prolonged times, contrary to routine methods (high temperature, short time). Our method also preserved antioxidant capacity, possibly by avoiding chemical changes/degradation due to high temperatures. This process can be used to produce organoleptically acceptable functional beverages that deliver a varied phenolic compound profile to the consumer.
Assuntos
Bebidas/análise , Camellia sinensis/química , Manipulação de Alimentos/métodos , Hibiscus/química , Compostos Fitoquímicos/análise , Chá/química , Antocianinas/análise , Antioxidantes/análise , Flavonoides/análise , Flores/anatomia & histologia , Ácido Gálico/análise , Fenóis/análise , Extratos Vegetais/química , Folhas de Planta/química , PaladarRESUMO
It has been recognized that lactic acid bacteria exhibit antioxidant properties, which have been mainly endorsed to the intact viable bacteria. However, recent studies have shown that intracellular content (IC) may also be good sources of antioxidative metabolites, which may potentially contribute to oxidative homeostasis in vivo. Hence, the modulatory effect of the intracellular content of Lactobacillus casei CRL 431 (IC431) on aflatoxin B1 (AFB1)-induced oxidative stress in rats was evaluated on the basis of its influence on hepatic lipid peroxidation (LPO), antioxidant status-antioxidant capacity (TAC), catalase (CAT), and glutathione peroxidase (GPx) activities; and on the oxidative stress index (OSi). Results demonstrated that CAT and GPx activities, and TAC, determined in plasma samples, were significantly (P < 0.05) higher in rats treated with AFB1 plus IC431 (3.98 µM/min/mg protein, 1.88 µM/min/mg protein, and 238.7 µM Trolox equivalent, respectively) than AFB1-treated rats (3.47 µM/min/mg protein, 1.46 µM/min/mg protein, and 179.7 µM Trolox equivalent, respectively). Furthermore, plasma and liver tissue samples from rats treated with AFB1 plus IC431 showed significantly (P < 0.05) lower LPO values (52 and 51%, respectively) and OSi (59 and 51%, respectively) than AFB1-treated rats. Hence, our results proved that the intracellular content of Lact. casei CRL 431 contains metabolites that are capable to modulate the antioxidant defense systems in living organism, which may help to ameliorate the damage associated to AFB1-induced oxidative stress.
Assuntos
Aflatoxina B1/toxicidade , Lacticaseibacillus casei , Estresse Oxidativo/efeitos dos fármacos , Animais , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Lacticaseibacillus casei/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Ratos , Ratos WistarRESUMO
Milk-derived bioactive peptides with a single activity (e.g., antioxidant, immunomodulatory, or antimicrobial) have been previously well documented; however, few studies describe multifunctional bioactive peptides, which may be preferred over single-activity peptides, as they can simultaneously trigger, modulate, or inhibit multiple physiological pathways. Hence, the aim of this study was to assess the anti-inflammatory, antihemolytic, antioxidant, antimutagenic, and antimicrobial activities of crude extracts (CE) and peptide fractions (<3 and 3-10 kDa) obtained from fermented milks with specific Lactobacillus plantarum strains. Overall, CE showed higher activity than both peptide fractions (<3 and 3-10 kDa) in most of the activities assessed. Furthermore, activity of <3 kDa was generally higher, or at least equal, to the 3 to 10 kDa peptide fractions. In particular, L. plantarum 55 crude extract or their fractions showed the higher anti-inflammatory (723.68-1,759.43µg/mL of diclofenac sodium equivalents), antihemolytic (36.65-74.45% of inhibition), and antioxidant activity [282.8-362.3µmol of Trolox (Sigma-Aldrich, St. Louis, MO) equivalents]. These results provide valuable evidence of multifunctional role of peptides derived of fermented milk by the action of specific L. plantarum strains. Thus, they may be considered for the development of biotechnological products to be used to reduce the risk of disease or to enhance a certain physiological function.
Assuntos
Produtos Fermentados do Leite/análise , Lactobacillus plantarum/fisiologia , Peptídeos/análise , Animais , Anti-Infecciosos/análise , Anti-Inflamatórios/análise , Antimutagênicos/análise , Antioxidantes/análise , Fermentação , Lactobacillus plantarum/genética , Leite/química , Proteínas do Leite/análiseRESUMO
The aim of this study was to evaluate the capability of Lactobacillus reuteri NRRL 14171 and Lactobacillus casei Shirota to remove dietary acrylamide (AA) under simulated gastrointestinal conditions using a dynamic system. The effects of different AA levels or bacteria concentration on toxin removal by Lactobacillus strains were assessed. Thereafter, AA-removing capability of bacteria strains under either fasting or postprandial simulated gastrointestinal conditions was evaluated. Commercial potato chips were analyzed for their AA content, and then used as a food model. Average AA content (34,162µg/kg) in potato chips exceeded by ca. 34-fold the indicative values recommended by the EU. Toxin removal ability was dependent on AA content and bacterial cell concentration. A reduction on bacterial viability was observed in the food model and at the end of both digestive processes evaluated. However, bacteria survived in enough concentrations to remove part of the toxin (32-73%). Both bacterial strains were able to remove AA under different simulated gastrointestinal conditions, being L. casei Shirota the most effective (ca. 70% removal). These findings confirmed the risk of potato chips as dietary AA exposure for consumers, and that strains of the genus Lactobacillus could be employed to reduce the bioavailability of dietary AA.
Assuntos
Acrilamida/metabolismo , Trato Gastrointestinal/microbiologia , Lacticaseibacillus casei/crescimento & desenvolvimento , Lacticaseibacillus casei/metabolismo , Limosilactobacillus reuteri/crescimento & desenvolvimento , Limosilactobacillus reuteri/metabolismo , Acrilamida/toxicidade , Biotransformação , Contaminação de Alimentos , Viabilidade Microbiana/efeitos dos fármacos , Modelos Biológicos , Modelos Teóricos , Solanum tuberosumRESUMO
Conjugated linoleic acid (CLA) has been shown to provide beneficial effects on health; however, the amount consumed in food is far from that required for the desired effects. Thus, increasing the CLA content in dairy foods through milk fermentation with specific lactic acid bacteria (LAB) offers an interesting alternative. Moreover, some LAB may be able to adhere to the intestinal mucosa and produce CLA through endogenous synthesis. Therefore, the objective of this study was to screen LAB isolates for their ability to produce CLA in skim milk and in simulated gastrointestinal conditions. Additionally, the ability of selected CLA-producing LAB to adhere to the intestinal mucosa in a murine model was assessed. Results showed that of 13 strains of Lactobacillus tested, only 4 were able to produce CLA in skim milk supplemented with linoleic acid (13.44 ± 0.78 to 50.9 ± 0.26 µg/mL). Furthermore, these 4 Lactobacillus strains were able to survive and produce CLA in simulated gastrointestinal conditions and to adhere to the intestinal mucosa of Wistar rats after 7 d of oral inoculation with fluorescently labeled bacteria. Accordingly, these 4 Lactobacillus strains may be used to manufacture fermented dairy foods to increase CLA content, and consumption of these fermented milks may result in CLA produced endogenously by these LAB.
Assuntos
Intestino Delgado/microbiologia , Lactobacillus/fisiologia , Ácidos Linoleicos Conjugados/metabolismo , Leite/química , Animais , Aderência Bacteriana , Produtos Fermentados do Leite/química , Fermentação , Lactobacillus/genética , Masculino , Leite/microbiologia , Distribuição Aleatória , Ratos , Ratos Wistar/metabolismo , Ratos Wistar/microbiologiaRESUMO
Dietary fiber and phenolic compounds are two recognized dietary factors responsible for potential effects on human health; therefore, they have been widely used to increase functionality of some foods. This paper focuses on showing the use of both substances as functional ingredients for enriching foods, and at the same time, describes the use of a single material that combines the properties of the two types of substances. The last part of the work describes some facts related to the interaction between dietary fiber and phenolic compounds, which could affect the bioaccessibility and absorption of phenolics in the gut. In this sense, the purpose of the present review is to compile and analyze evidence relating to the use of dietary fiber and phenolic compounds to enhance technological and nutritional properties of foods and hypothesize some of the possible effects in the gut after their ingestion.
Assuntos
Fibras na Dieta/administração & dosagem , Fenóis/administração & dosagem , Fibras na Dieta/análise , Ingestão de Alimentos/fisiologia , Frutas/química , Trato Gastrointestinal/fisiologia , Humanos , Fenóis/análiseRESUMO
Cheese yield mainly depends on the amount and proportion of milk constituents; however, genetic variants of the proteins present in milk may also have an important effect. The objective of this research was to study the effect of the variants A and B of ß-lactoglobulin (LG) on cheese yield using a model system consisting of skim milk powder fortified with different levels of a mixture containing α-lactalbumin and ß-LG genetic variants (A, B, or A-B) in a 1:2 ratio. Fortified milk samples were subjected to pasteurization at 65 °C for 30 min. Miniature cheeses were made by acidifying (pH=5.9) fortified milk and incubating with rennet for 1h at 32 °C. The clot formed was cut, centrifuged at 2,600 × g for 30 min at 20 °C and drained for determining cheese yield. Cheese-yielding capacity was expressed as actual yield (grams of cheese curd per 100g of milk) and dry weight yield (grams of dried cheese curd per 100g of milk). Free-zone capillary electrophoresis was used for determining ß-LG A or B recovery in the curd during rennet-induced coagulation. The presence of ß-LG variant B resulted in a significantly higher actual and dried weight cheese yield than when A or A-B were present at levels ≤ 0.675% of whey protein (WP) addition. Results of free-zone capillary electrophoresis allowed us to infer that ß-LG B associates with the casein micelles during renneting, as shown by an increase in the recovery of this variant in the curd when ß-LG B was added up to a maximum at 0.45% (equivalent to 0.675% WP). In general, actual or dried weight cheese yield increased as WP addition was increased from 0.225 to 0.675%. However, when WP addition ranged from 0.675 to 0.90%, a drastic drop in cheese yield was observed. This behavior may be because an increase in the aggregation of casein micelles with a concomitant inclusion of whey protein in the gel occurs at low levels of WP addition, whereas once the association of WP with the casein micelles reach a saturation point at addition levels higher than 0.675%, rearrangements of the gel network result in larger whey expulsion and syneresis. This knowledge is expected to be useful to maximize cheese yield and optimize processing conditions during cheese and cheese analogs manufacturing.
Assuntos
Queijo/análise , Lactoglobulinas/genética , Proteínas do Leite/genética , Leite/química , Animais , Caseínas/metabolismo , Queijo/normas , Indústria de Laticínios , Eletroforese Capilar , Proteínas do Leite/química , Pasteurização , Proteínas do Soro do LeiteRESUMO
The antihypertensive and hypolipidemic effects of milk fermented by specific Lactococcus lactis strains in spontaneously hypertensive rats (SHR) were investigated. The SHR were fed ad libitum milk fermented by Lc. lactis NRRL B-50571, Lc. lactis NRRL B-50572, Captopril (40mg/kg of body weight, Sigma-Aldrich Co., St. Louis, MO) or purified water for 4 wk. Results suggested that Lc. lactis fermented milks presented a significant blood pressure-lowering effect. No significant difference was noted among milk fermented by Lc. lactis NRRL B-50571 and Captopril by the second and third week of treatment. Additionally, milk fermented by Lc. lactis strains modified SHR lipid profiles. Milk fermented by Lc. lactis NRRL B-50571 and B-50572 were able to reduce plasma low-density lipoprotein cholesterol and triglyceride contents. Thus, milk fermented by Lc. lactis strains may be a coadjuvant in the reduction of hypertension and hyperlipidemia and may be used as a functional food for better cardiovascular health.
Assuntos
Anti-Hipertensivos/administração & dosagem , Fermentação , Hipolipemiantes/administração & dosagem , Lactococcus lactis/metabolismo , Leite/metabolismo , Leite/microbiologia , Animais , Pressão Sanguínea , Produtos Fermentados do Leite/química , Hipertensão/terapia , Lipídeos/sangue , Masculino , Leite/química , Ratos , Ratos Endogâmicos SHR , Triglicerídeos/sangueRESUMO
Previous studies have demonstrated that milk fermented by specific Lactococcus lactis strains significantly inhibits the activity of angiotensin I-converting enzyme (ACE). However, the relationship between the ACE inhibitor and its in vivo action has revealed discrepancies. Therefore, the aim of the present study was to investigate the antihypertensive and heart rate (HR)-lowering effect of milk fermented by specific L. lactis in a murine model. Spontaneously hypertensive male rats (271 (SD14) g) were randomised into four treatment groups that were orally administered with milk fermented by L. lactis NRRL B-50 571 or L. lactis NRRL B-50 572 at 35 or 50 mg protein/kg body weight (BW), respectively. Further, two more groups were fed with different solutions as controls: a saline solution as the negative control and Captopril (40 mg/kg BW), a proven ACE inhibitor, as the positive control. Blood pressure and HR were monitored by the tail-cuff method before the treatments and at 2, 4, 6 and 24 h post-oral administration. The results demonstrated that milk fermented by L. lactis NRRL B-50 571 as well as by L. lactis NRRL B-50 572 presented an important systolic and diastolic blood pressure- and HR-lowering effect. Thus, milk fermented by specific L. lactis strains may present potential benefits in the prevention and treatment of CVD associated with hypertension in humans.
Assuntos
Produtos Fermentados do Leite , Frequência Cardíaca , Hipertensão/dietoterapia , Lactococcus lactis/metabolismo , Leite/microbiologia , Animais , Pressão Sanguínea , Doenças Cardiovasculares/dietoterapia , Doenças Cardiovasculares/prevenção & controle , Fermentação , Masculino , Ratos , Ratos Endogâmicos SHRRESUMO
The ability of specific wild Lactococcus lactis strains to hydrolyze milk proteins to release angiotensin I-converting enzyme (ACE) inhibitory peptides was evaluated. The peptide profiles were obtained from the <3 kDa water-soluble extract and subsequently fractionated by reversed-phase HPLC. The fractions with the lowest half-maximal inhibitory concentration estimated values (peptide concentration necessary to inhibit ACE activity by 50%) were Lc. lactis NRRL B-50571 fraction (F)1 (0.034 ± 0.002 µg/mL; mean ± SD) and Lc. lactis NRRL B-50572B F 0005 (0.041 ± 0.003 µg/mL; mean ± SD). All peptide fractions were analyzed by reversed-phase HPLC tandem mass spectrometry. Twenty-one novel peptide sequences associated with ACE inhibitory (ACEI) activity were identified. Several novel ACEI peptides presented peptides encrypted with proven hypotensive activity. In conclusion, specific wild Lc. lactis strains were able to hydrolyze milk proteins to generate potent ACEI peptides. However, further studies are necessary to find out the relationship between Lc. lactis strain proteolytic systems and their ability to biogenerate hypotensive peptides.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/análise , Lactococcus lactis/metabolismo , Leite/microbiologia , Peptídeos/análise , Animais , Bovinos , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Fermentação , Leite/química , Leite/metabolismo , Peptidil Dipeptidase A/metabolismo , Espectrometria de Massas em Tandem/métodosRESUMO
Traceability ensures a link between carcass, quarters or cuts of beef and the individual animal or the group of animals from which they are derived. Meat traceability is an essential tool for successful identification and recall of contaminated products from the market during a food crisis. Meat traceability is also extremely important for protection and value enhancement of good-quality brands. Molecular meat traceability would allow verification of conventional methods used for beef tracing in synthetic Mexican bovine breeds. We evaluated a set of 11 microsatellites for their ability to identify animals belonging to these synthetic breeds, Brangus and Charolais/Brahman (78 animals). Seven microsatellite markers allowed sample discrimination with a match probability, defined as the probability of finding two individuals sharing by chance the same genotypic profile, of 10(-8). The practical application of the marker set was evaluated by testing eight samples from carcasses and pieces of meat at the slaughterhouse and at the point of sale. The DNA profiles of the two samples obtained at these two different points in the production-commercialization chain always proved that they came from the same animal.
Assuntos
Bovinos/genética , Impressões Digitais de DNA/métodos , Genótipo , Repetições de Microssatélites/genética , Animais , Cruzamento , Feminino , Masculino , Carne , Indústria de Embalagem de Carne/métodos , Recall e Retirada de ProdutoRESUMO
The objective of this study was to evaluate if Mexican Fresco cheese manufactured with specific lactic acid bacteria (LAB) presented angiotensin I-converting enzyme inhibitory (ACEI) activity. Water-soluble extracts (3 kDa) obtained from Mexican Fresco cheese prepared with specific LAB (Lactococcus, Lactobacillus, Enterococcus, and mixtures: Lactococcus-Lactobacillus and Lactococcus-Enterococcus) were evaluated for ACEI activity. Specific peptide fractions with high ACEI were analyzed using reverse phase-HPLC coupled to mass spectrometry for determination of amino acid sequence. Cheese containing Enterococcus faecium or a Lactococcus lactis ssp. lactis-Enterococcus faecium mixture showed the largest number of fractions with ACEI activity and the lowest half-maximal inhibitory concentration (IC(50); <10 µg/mL). Various ACEI peptides derived from ß-casein [(f(193-205), f(193-207), and f(193-209)] and α(S1)-casein [f(1-15), f(1-22), f(14-23), and f(24-34)] were found. The Mexican Fresco cheese manufactured with specific LAB strains produced peptides with potential antihypertensive activity.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/análise , Queijo/análise , Queijo/normas , Cromatografia Líquida de Alta Pressão , Manipulação de Alimentos/métodos , Proteínas do Leite/análise , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Angiotensin I-converting enzyme inhibitory (ACEI) activity was evaluated and compared in <3 KDa water-soluble extracts (WSE) isolated from milk fermented by wild and commercial starter culture Lactococcus lactis strains after 48 h of incubation. The highest ACEI activities were found in WSE from milk inoculated with wild L. lactis strains isolated from artisanal dairy products and commercial starter cultures. On the other hand, the lowest ACEI activities were found in WSE from milk inoculated with wild strains isolated from vegetables. Moreover, the IC(50) values (concentration that inhibits 50% activity) of WSE from artisanal dairy products were the lowest, indicating that these fractions were the most effective in inhibiting 50% of ACE activity. In fact, a strain isolated from artisanal cheese presented the lowest IC(50) (13 µg/mL). Thus, it appears that wild L. lactis strains isolated from artisanal dairy products and commercial starter cultures showed good potential for the production of fermented dairy products with ACEI properties.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/metabolismo , Microbiologia de Alimentos , Lactococcus lactis/metabolismo , Leite/microbiologia , Angiotensina I/metabolismo , Animais , Fermentação , Lactococcus lactis/classificaçãoRESUMO
Production of new protein-based products for special nutrition such as hypoallergenic infant formulas, fortified beverages and nutraceutics, require ideal ingredients. Protein ingredients were developed by enzymatic hydrolysis and methionine synthesis of soy protein. Hydrolysis was done at 4% (w/v) using porcine pancreatic enzymes (4% w/w), 50 degrees C, 6 h and pH 8. After drying powder was resuspended (20% w/v) and incubated with 7.6% (w/w) methionine methyl-ester, 1% (w/w) chymotrypsin and 3 M glycerol, 37 degrees C, 3 h and pH 7. Hydrolysates were fractionated by ultrafiltration (UF) before and after enrichment (E): FI > 10, 10 > FII > 3 and 3 > FIII > 1 kDa. Functional properties, amino acid content, anti-physiological factor activities and antigenicity were assayed for all the UF fractions and the soybean meal. Protein quality bioassay and sensorial test of an non-enriched fraction and an enriched fraction were performed. Functional properties were positively modified by hydrolysis and synthesis by using a minimum time and methionine added for the last reaction. After UF all the fractions under 10 kDa showed 100% solubility (pH 4 and 7), good clarity, acceptable foam capacity and negligible antigenicity and antiphysiological activities. Additionally, methionine enrichment enhanced their nutritional value, upgrading sulfur amino acid requirements for infants and adults. Because functionality and nutritional value FIII-E could be used for hypoallergenic infant formulas, FII-E for fortified soluble formulas and nutraceutics and FI-E for a semi-solid baby food.